TinyCAD – Open-Source Schematic Capture
TinyCAD is a program to help you draw circuit diagrams. It comes complete with symbol libraries to get you started straight away.
Features to make it easier for you to put your circuit diagrams on your own web-site or adding them to your Word or other documents. TinyCAD supports outputing ciruits diagrams as PNG files.
Can be used to make circuit diagrams that can be fed in to a PCB layout program. You can export from TinyCAD in Protel, PADS, Eagle SCR format. You can also use TinyCAD to create Spice simulation files.